Patent literature 1 discloses a driving circuit for driving an insulated gate semiconductor element. This driving circuit allows applying a reverse bias voltage at a turn-off with a simple structure employing a single dc power supply.
The driving circuit disclosed in patent literature 1 drives an insulated gate semiconductor element that controls, in response to the gate voltage, an electric current flowing between the emitter connected to the ground-line and the collector to which a given voltage is applied. This driving circuit comprises the following structural elements:                a pair of transistors, connected in series between the ground line and a voltage line to which a dc voltage is applied, for controlling a gate voltage of the insulated gate semiconductor element;        a voltage clamping circuit for holding the gate voltage lower than the de voltage; and        a capacitor connected between the gate of the insulated gate semiconductor element and a junction point of the pair of transistors, and charged when the element is turned on while generating a reverse bias voltage when the insulated gate semiconductor element is turned off.        